Audible signal



Patented Mar. 1, 1949 AUDIBLE SIGNAL Peter C. Reck, Adrian, Mich., assigner, by mesne assignments, to Sperti Faraday Inc., a corporation of Ohio Application January 8, 1947, .Serial No. 720,799

3 Claims.

This invention relates to mountings, especially in establishing a denite tonal response to impacting, even selectively, for different audible signals in predetermined relation.

This invention has utility when incorporated in a multiple bar type of chime, involving interrelated features of the mountings for the bars, in association with resonant chamber carriers and self-retracting non-resonant vibration reacting impactors therefor.

Referring to the drawings:

Fig. 1 is a front View, with parts broken away, of an embodiment of the invention in a two-bar type of chime signal, adapted for different source cut-in switches, which may be from front and rear doors of a dwelling;

Fig. 2 is a side elevation of the unit of Fig. l, from the right, portions being removed;

Fig. 3 is a partial vertical section lengthwise thru one of the impactor coils and the hammer operable thereby;

Fig. 4 is a portion of an impactor coil mounting bracket, thru which the impactor plunger may operate;

Fig. 5 is a detail View in plan, looking down upon a grommet and its support, in providing a yieldable holder for a chime bar with sound dampening vibration against transmission therethru;

Fig. 6 is a fragmentary front elevation looking into the grommet mounting of the chime bar of Fig. 5; and

Fig. '7 is a Wiring diagram of the impactor control coils as incorporated in the unit of Fig. 1.

The housing A base member or plate I has upstanding side flange portions 2 upon which may be mounted clip brackets 3 by welding thereto on the sides toward each other. Simultaneous with the weld mounting of the brackets 3 upon the flange portions 2, annular flange-carrying resonant chamber sections 4 are also welded to the portions 2. Each section 4 has a port or central opening 5. Snugly slip-fitted to seat thereon is a complementary housing wall outer face 6 with a flange 'I :about the flange of the section 4. The resonant chamber is thus completed in the assembly of the portions 6, 1, which may be plated, as with chrome or nickel. It is thus seen that each cup shaped 2 portion 6, l, provides the outer wall for a resonant chamber having an inner wall or partition section 4.

A claw or angle portion strip 8 may be welded to the inner side of the upper wall 9 of an arc cover plate or shield Il provided with an inwardly directed side flange portion II nesting about the resonant chamber wall outer flange 'I. With the plate I against a room side wall, and the shield I0 hanging from the upper edge of the plate S, a lower inwardly arced portion I2 of the shield I6 completes the envelopment of the unit. In practice this shield Il! may be decorative, and is readily detached by swinging the lower portion I2 outward and lifting the portions 8 clear of the upper edge of the base I.

The chime bars Removal of the shield I0 exposes a chamber I3 between the anges 2 having the brackets 3. Chi-me bars I4, I5, are yieldably supported in this chamber I3 across the openings 5 as ports to the respective resonant chambers of the sections 4, 5, 6, 'I.

Openings I6 thru the chime bars I4, I5, have rubber grommets I'I therein, with the brackets 3 protruding therefrom in providing vibration transmission dampening mountings for the chime bars I 4, I5. Applicant attributes importance to establishing and maintaining tone value relation, especially as between the different chimes of a unit. In a tWo-bar assembly as herein disclosed, major third interval, or 5:4 ratio is taken, as between the notes C and E, with also C# to F. It is thus seen that for a normal scale with C 261.62 cycles per second, the frequency for E would be 329.88 per second.

Chime bars, deep case-hardened to Rockwell test -65, as oarburized and water quenched, have been taken at .09 thickness and 1.25 width. For overall length for C note, the bar I5 is 58'75"; and for E note, the bar I4 is 5.125". The center to center spacing between the openings Ii of the bar I5, for appropriate node length is taken as 3.25 for the note C. 'Ihe openings I6 of the bar M for the note E are spaced 2.875". In the disclosure herein, the bars E4, I5, are not horizontal, but suspended. Adopting the support for the C note chime bar as tangent to the upper side of its upper opening I6, and this modified by the compression of the rubber of the grommet I'I, places the operating center of the upper opening i6 at 1.413 down from the top. However, for the higher note E, the compression of the grommet seems to be less a factor to be cured, and there is a more near approach to half diameter locus for the proper node length factor. This determines the spacing of the upper opening center i6 for the bar I4 as 1.289" down from the top. These top portions, as so dimensioned, are in frequency with the tone emanating from the node and accordingly do not react to quench node performance of the bar.

The impactors Located in the chamber I3 between the chime bars I4, I5, is a minor housing I8, in which are located coils I9, 20, positioned by cadmium plated steel angle brackets 2|, 22, having'` screws 23 assembling the brackets and thus the coils in the shell or housing I8. Axially extending to protrude both ways from each coil I9, 29, is a brass guide or tube 24. The coils I9, 2B, have insulation end disks 25 spacing the magnetizable brackets 2l, 22, from the windings of the respective coils. A solenoid core plunger magnet 25 has a plastic hammer or stem 21, projecting from the end of the coil. This normally projecting non-magnetic extension has its end embedded in the end of the core 25. The other end of the core 25, at non-energized position therefor, is laterally from its coil and in the guide 24 to protrude outward therefrom, say away from the bar lil and toward the bar I5. f

llt is the purpose to have the plunger or core 26 of a length only slightly exceeding the length `oi its coil I5, or 20. An aluminum extension 28 provides a non-magnetic additional length terminally to receive, as to the coil I5, a cellulose acetate tip 29 or other suitable plastic embedded therein, as the striker portion of the hammer or the chime bar I5. A tension helical spring 35 is anchored in a groove of the portion 28 adjacent the tip 29 and encircling the portion 28. The protruding portion of the core 26 and. the sleeve 24 are outward from the bracket 22 as to the coils. The opposite end of the spring 30 from the portion 2E rests upon the bracket 22. Upon energizing either coil I9, 20, the tip 21 for the plunger 23 in such coil, effects compression of the spring 35 as the chime bar I4 is struck. The recovery therefrom, as to vthe coil I9, is an impacting of the chime bar I5 by the tip 29.A Upon de-ener'gizing of the coil IS, the spring 3B retracts the tip 29 clear of the bar I5, but with the major extent or the core 25 in that portion of the sleeve 21% away from the coil I9, and protruding even beyond the sleeve 24.

In the matter of the plunger 26 Vin the coil 2li, in lieu of the selected plastic tip 29, there is here a sponge rubber tip 3i, as a dampener against transmission of impact vibration to or from the chime bar I5. Practically, this means that upon energizing of the coil i9, there is a two-tone audible signal, harmonious in a major third interval. While, upon energizingV of the coil 20, there is in response but a Vsingle tone o'r note, that of the bar M. As with the plunger 26 in the coil le, this plunger 26 in the coil 20, at deenergizing of the coil 2U, has an idle position clear for each of its tips 2l, 3l, to be away from the bars M, I5.

Hum or impactor tonal disturbance of the signal is rendered negligible by the temporary magnetic influence of the brackets 2l, 22.

with 'a clearance region 32 above a seat 33 for the sleeve 24, the magnetic flux is unbalanced. The lower side of the plunger 26 has magnetic circuit therefrom to the bracket seat 33. This downward magnetic flux supplements the weight or gravity of the plunger and tends to defeat iioating chatter.

The electric circuit Sixty cycle one hundred twenty volt alternating electric current supply lines 34, 35, are to a transformer 36 to step down the voltage into the range of six to eight volts, as a normal house signal circuit. A conductor 3'I from the transformer 36 extends to a terminal 38 at a lower portion of the housing I8 in the chamber I3. Leads 39, 40, from the terminal 38, connect respectively to the coils I9, 20. From the other side of the transformer -35, a line il extends to a push button switch d'2 having a connection by a line 43 to a terminal 44 at the housing I8 for a lead 55 therefrom to the coil I9. Additionally, from the line 4I is a switch 46 in a line lll to a terminal 48 at the housing I8. From the terminal 48, a line 49 extends to the coil 29. In practice, say for residence audible signal purposes, a switch 42 may be for the front entrance, which, as operated, energizes the coil I9, for the striker therein to impact both chime bars Ill, I5, for a two-tone major third interval harmonious sounding of notes. For the purpose of enabling one to locate diierent sources or" calling, the rear entrance of the home may have a second switch for sound- -ing a single note. The closing of the switch 45 does not disturb the coil I9 nor its plunger, but acts solely upon the coil 20. While the striker in the coil 25 has freedom for reciprocation, its deadened end oi tip 3| as toward the chime bar I5, nullies any impact at this region. The lresult is that the plunger tip 21 strikes the bar I4 for a single distinctive note to be sounded. The householder is thereby enabled' readily to detect the call for attention is 'from the rear door. The springs 38 render the plungers or strikers self- `resetting to an idle, oating non-contacting position as to the chime bars I4, I 5, once the actuating switch 'is released.

What is claimed and it is desired to secure by Letters Patent is:

1. An audible signal unit comprising a base plate vertical back having a pair of side flanges leaving an upwardly open channel, each of the flanges having mounted thereon an outwardly anged chamber section, complementary chamber sections telescoped thereon to form outwardly from the respective flanged chamber sections a resonant chamber between the flanged section and the relatively telescopic section, in said 'channel between the side anges a pair of suspended chime bars, one in proximity to each resonant chamber, a shield for the bars, carried by the base plate and nesting over the resonant chambers, and horizontally reciprocable electromagnetic strikers for the bars.

2. For an 'audible signal 'actuator embodying means to be impacted, 'said actuator comprising ain alternating electric current energizing source, a coil to be energized, fa plunger in the 'coil to act upon the means to be impacted, magnetic material vend means for the coil having lateral air gap upward from the plunger in providing downward lux to supplement gravity in stabilizing the plunger from hum generating -oating movement, otherwise ytending to arise due to harmonics from 'the current. A

2,463,203 5 6 3. An audible signal comprising in horizontal assembly a resonant chamber means, a chime REFERENCES CITED bar, a striker, a second chime bar, therebeyond The following references are of record in the a second resonant chamber means, a shield spanfile of this patent: ning the chambers to bridge therebetween and 5 UNITED STATES PATENTS enclose the bars and strikers, said striker including a pulsating electric current energized coil, a NUI-fibel Name Date plunger core magnet, and magnetic guide brackets 1,994,559 Bergeron et al Mar 19, 1935 therefor having upper side argap clearance for 2,139,131 RteUhOuSe "F6116, 1940 unbalancing magnetic flux to supplement gravity 10 2,227,227 Mason DSC. 31, 1940 in quenching pulsation harmonic hum from the 2,245,453 Warren June 10, 1941 magnet. 2,265,815 Rittenhouse Dec. 9, 1941 PETER C. RECK. 

